Xenbase Image ID: 148478

Fig. S6. KCNE1 expression induces neoplastic-like phenotypes in melanocytes. Embryos exposed to RL-3 (an activator of KCNQ1) express slightly fewer melanocytes in the neural tube (A) and many fewer melanocytes in the tail (A ), compared with Fig. 3 A and A . Closer examination of sections taken through the neural tube (B) revealed that melanocytes of KCNE1-injected larvae often dropped down and invaded the dense nervous tissues of the neural tube (green arrows). Blue stain in B indicates lineage label that was coinjected with KCNE1 mRNA. Sections through the gut indicate the presence of numerous melanocytes (D, arrowheads) in KCNE1-injected larvae, where control embryos have none (C). During the second week of development, the excess melanocytes continue to migrate and spread out. They leave the trunk core and invade the dorsal fin (E, red arrowheads). Occasionally, KCNE1-misexpressing animals exhibited small growths on their outer surface, which often contained a core of melanocytes within (F, green arrowheads). When larvae were grown for 3 months, the hyperpigmentation and metastasis phenotype continued, and the ectopic melanocytes were seen to colonize the blood vessels: controls are shown in G (white arrows indicate lack of melanocytes in blood vessels), whereas KCNE1-injected larvae are shown in whole mount in H (red arrows indicate melanocytes throughout the ventral vessels). Higher magnification (H ) reveals melanocytes completely encircling the vessel. Melanocytes also spread throughout the epidermal layers of the animal (compare control in I with KCNE1-injected shown in J). Several particular internal organ primordia are frequently invaded, such as the pronephros and lateral ganglia (higher-magnification indicated by green arrow, shown in J ). Yellow plus signs indicate tissues from KCNE1-injected embryos; minus signs indicate control tissues. NT, neural tube; LP, lateral plate; vp, velar plate. Image published in: Morokuma J et al. (2008) Copyright © 2008. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View

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